THE AQUARIUM, JULY, 1896. 



61 



the precautions taken by the eels, 

 many of them became fringed with 

 hundreds of the leeches. I have seen 

 the eels repeatedly loop themselves so 

 as to bring the head and tail together, 

 in which position they would strip off 

 the leeches with their teeth ; and in so 

 doing they often bit or tore off small 

 pieces of their flesh and fins, so that in 

 course of time (when the wounds did 

 not heal rapidly) they became badly 

 covered with fungus. What with the 

 leeches and fungus the eels had become 

 floating skeletons. To save the few re- 

 maining I placed them in the "hospital 

 tank" for treatment. The course of 

 treatment was to rapidly pass them 

 through a bath of warm and very salt 

 water (a nearly saturated solution.) 

 This salt bath 1 never knew to fail in 

 destroying leeches and fungus, if the 

 fish so treated were not too far gone. 



The bottom of the "hospital tank " 

 contained a heavy flooring of Coney 

 Island sand,* in which the eels imbed- 

 ded themselves as if only too glad to 

 take a rest after their long suspension. 

 At night they were fed to repletion on 

 raw beef. Under this treatment they 

 soon became "solid" and happy. 



The tank out of which the eels were 

 taken was then cleared of all the fish 

 remaining, after which a half barrel of 

 quicklime was cast into it, and in one 

 hour's time the lime had done its work, 

 everything living was burnt up, the 

 tank was then drawn off, scrubbed, 

 and washed out, and a heavy bottom 

 of fine sand introduced. 



One of the most beautiful tanks I 

 ever had, and of which I was very 

 proud, contained some twenty-five 

 weakfish, thirty kingfish, twenty striped 

 bass, two pilotfish, and several bluefish. 



* Fine white sand. — Ed. 



They were all in perfect health, high 

 color, and feeding well. In one night 

 all the kingfish died ; the next day the 

 weakfish departed, then the pilots and 

 the blues. 



I had nothing in the way of an ex- 

 planation, as I had never in all my long 

 experience known of fish dying in this 

 unaccountable manner. I examined 

 the dead fish carefully ; both externally 

 and internally they appeared to be in 

 perfect health ; their gills seemed to be 

 unusually healthy for fish kept so long 

 in confinement. 



Next to this tank was a tank of 

 plump and healthy blackfish, who wt-re 

 fed as blackfish were never fed before ; 

 and these, too, died in the same unac- 

 countable manner a short time after 

 the other fish. 



Next to the blackfish was a tank con- 

 taining over one hundred spotted cod- 

 lings, and who were so fat that they sel- 

 dom swam for more than five minutes 

 at a time without resting half an hour 

 to take breath. 



A day or two after the death of the 

 weakfish, kingfish, and blackfish, the 

 codlings began to go. Every few min- 

 utes through the day my assistant was 

 scooping out dead fish. Still I could 

 not detect the cause, but I came to the 

 conclusion that when blackfish and cod- 

 lings (the toughest of all aquarium fish) 

 die, the reason ought to be discovered. 



All of these fish, from their first ill- 

 ness, had been fed on the very choicest 

 of marine diet — soft crabs, shrimp, hard 

 and soft clams, and even oysters and 

 scallops. The codlings would churn 

 the surface of the water when fed on 

 soft crab, so keen were their appetites, 

 and yet a minute after they would re- 

 tire to the bottom of the tank, straighten 

 out and die. I watched the codlings 

 with painful anxiety, for I began to 



